You know the common first program given in any class displays the phrase
Hello World on the computer screen?
Yeah, that’s starting them off right. With a defect.
The “world” is a noun of direct address. Ergo, the phrase lacks a comma and should be
Speaking of classes, I’ve taken a couple or four language programming classes in the community college, and although they’ve focused on writing applications (or ceaselessly computing meaningless formulas using Java arrays) that do what they’re supposed to, but instructors never mentioned implications of quality assurance and testing. Maybe they thought the program would include it later, but at the time (the late 1990s), kids were coming into the field with nothing but those couple of classes at the community college. Those same kids are now the VPs. Makes sense, don’t you think?